Research Of Railway Embankment Slope Based On Limit State Design Method Under Water Immersion

The stability of the slope is paid much attention in the field of geotechnical engineering.With the continuous promotion and application of domestic railway technology in the world,the traditional design method of safety factor is gradually being replaced by the limit state design method of slope based on reliability theory.The comprehensive evaluation of slope stability with the safety factor and the reliability index can reflect the fact of engineer better.In this paper,based on Provisional Code for Limit State Design Method of Railway Subgrade(Q/CR9127-2015),a lot of research on the design method of the limit state of the railway embankment slope under water immersion is studied,which provides reference for the subsequent relevant regulations.In this paper,the limit state equation of stability analysis of the railway embankment slope under water immersion is determined by Swedish slice method.Furthermore,the “JC method” is used to calculate the slope reliability index under five kinds of track types respectively.Then the general separation method is used to calculate and calibrate the sub-coefficients,and the reference values are given.Finally,the sensitivity analysis of the influencing factors is carried out in accordance with water immersion.(1)The data is consulted,and the variables that affect the stability of the railway embankment slope is determined,the limit state equation of the railway embankment slope under water immersion is deduced by using the theory of Swedish slice method.(2)A Matlab calculation program is compiled by JC method,the reliability indexes of five kinds of slopes are calculated in turn,including: super heavy,heavy,secondary heavy,medium and light slope under water immersion,and the corresponding reference values are obtained statistically.(3)The general separation method is used to calculate the sub-coefficient of five kinds of slopes under water immersion.The computed results are calibrated and the reasonable of the reference values are determined.(4)A Matlab program is compiled,and the influence of the variation of train load and the soil parameters,as well as the differences between the upstream and downstream sides of the slope on the reliability index of the five kinds of slopes under water immersion are analyzed in sequence.The analysis shows that the variability of the shear strength indicators ? has a great influence on the reliable index.The change of the water level difference has certain influence on the reliable index and the safety coefficient.In the actual project,attention should be paid to the change of water level in time.